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public device. A device that is attached to a fabric or
switch, and can communicate to that fabric or switch. A
public device can be part of an arbitrated loop topology
or point-to-point topology.
Q
quiesce. To put a device into a temporarily inactive or
inhibited state, but not remove it from the server.
R
read. To acquire or interpret data from a storage
device, from a data medium, or from another source.
reboot. To reinitialize the execution of a program by
repeating the initial program load (IPL) operation.
record. The smallest distinct set of data bytes that is
supplied from a server for processing and recording by
a tape drive, and the smallest distinct set of data to be
read from tape, reprocessed, and made available to a
server by a tape drive.
record boundaries. The fixed limits of a record.
relative humidity. The ratio of the amount of water
vapor actually present in the air to the greatest amount
possible at the same temperature.
repeater. A device that regenerates signals to extend
the range of transmission between data stations or to
interconnect two branches. A repeater is a node of a
local area network.
reset. To return a device or circuit to a clear state.
LDI wrap plug. A connector mechanism that connects
to an LDI port for the purpose of testing the drive's
circuitry for the LDI interface.
LDI wrap test. A diagnostic that can be run on the
drive to determine whether the circuitry functions
properly to and from the LDI connector.
S
s. See second.
SAN. See Storage Area Network.
SAN Data Gateway. A device that provides Fibre
Channel attachment between Open Systems servers and
SCSI disk and tape storage systems.
SC. See subscription channel connector.
scratch cartridge. A data cartridge that contains no
useful data, but can be written to with new data.
SCSI. See Small Computer Systems Interface.
SCSI bus. (1) A collection of wires through which
data is transmitted from one part of a computer to
another. (2) A generic term that refers to the complete
set of signals that define the activity of the Small
Computer Systems Interface (SCSI).
SCSI connector. Located at the rear of the drive, the
connector that facilitates commands to and from the
server, and to which the internal SCSI cable of an
enclosure connects.
SCSI device. Anything that can connect into the SCSI
bus and actively participate in bus activity.
SCSI drive sense data. In response to inquiry from
the server about an error condition, a packet of SCSI
sense bytes that contains information about the error
and that is sent back to the server by the drive.
SCSI ID. The unique address (from 1 to 15) that you
assign to an drive that uses a SCSI interface (Model
T400).
SCSI ID connector. Located at the rear of the drive,
the connector that enables the drive's SCSI address to
be set. Addresses are determined by the placement of
jumpers on the pins.
SCSI interface. See Small Computer Systems Interface.
SCSI protocol. A set of rules that control the
communication and transfer of data between two or
more SCSI devices or systems in a communications
network.
SCSI ID switch. Located on an enclosure that
contains a drive, a mechanism that connects to the
drive and allows you to change the drive's SCSI ID
without using jumpers.
SCSI log sense data. In response to inquiry from the
server about the drive's error logs and counters, a
packet of SCSI sense bytes which contains that
information and which is sent back to the server by the
drive. Log sense data is used to diagnose problems,
especially if the problems are intermittent.
SCSI wrap plug. A connector mechanism that
connects to a SCSI port for the purpose of testing the
drive's circuitry for the SCSI interface.
SCSI wrap test. A diagnostic that can be run on the
drive to determine whether the circuitry functions
properly to and from the SCSI connector.
second. One sixtieth of a minute.
selection time-out. Following the selection of an
option (for example, a data transfer), the period of time
during which it is determined that there is a bad
connection between the server and the drive.
125
Glossary
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